Ischemia with No Obstructive Arteries (INOCA): A Review of the Prevalence, Diagnosis and Management

Ischemia with no obstructive arteries (INOCA) is defined as patients with angiographic evidence of ischemia but no obstructive coronary artery disease (CAD) at coronary angiography. INOCA is estimated to be prevalent is 3-4 million individuals with a female predominance. INOCA is composed of different endotypes including: microvascular dysfunction, vasospasm and a combination of the 2. Diagnosis of INOCA requires either non-invasive or invasive techniques aimed at assessing coronary flow reserve (CFR), Index of Microcirculatory Resistance (IMR) and spasm secondary to acetylcholine injection. Although INOCA is associated with an increased risk of MACE and a decrease in quality of life, less than half of patients are appropriately treated. Treatment of INOCA remains elusive with current therapeutics tailored towards the specific endotype and ongoing clinical trials looking to assess the efficacy of traditional CAD medications.